胰酶活化机制的研究进展

胰酶活化是急性胰腺炎发病的始动环节，胰酶活化可发生于胰管，间质及细胞内，胰管内胰酶活化，可能不足以诱发ＡＰ。细胞内胰酶活化可能是水肿型ＡＰ的主要机制，间质内胰酶活化可能促使水肿型ＡＰ转化为坏死型ＡＰ。阐明胰酶的活化机制，对于ＡＰ的治疗具有重要的指导意义。     

西地那非、伐地那非或他达拉非通过诱导磷酸二酯酶5的构象变化促进其磷酸化

Bessay等进行了一项研究证实：西地那非、伐地那非或他达拉非通过诱导磷酸二酯酶5（PDE5）的构象变化促进其磷酸化。研究通过移人一种非变性聚丙烯酰胺凝胶和一种能使构象发生变化的胰蛋白酶消化片段来证实：PDE5抑制剂（西地那非、伐地那非或他达拉非）或环核苷酸蛋白激酶依赖的磷酸化物都会引起明显的PDE5构象变化。环磷酸鸟苷（cGMP）和一种PDE5抑制剂所形成的复合体或PDE5的磷酸化物并不能引起进一步的凝胶阻抑或胰蛋白酶的继续消化；也不能引起进一步的PDE5磷酸化。     

磷脂酶A2在急性缺血性肾衰中的作用

磷脂酶Ａ２作为炎症反应的始动酶，在急性缺血性肾衰的发生发展中的有重要作用。本文综述了磷脂酶Ａ２的一般特性和在急性缺血性是能衰中的研究进展。     

巴曲酶复合低温对全脑缺血再灌注期间ATP酶活性的影响

目的 观察低温，巴英酶及巴曲酶复合低温对沙土鼠全脑缺血后海马组织Ｎａ＾＋－Ｋ＾＋－ＡＴＰ酶，Ｃａ６２＋－ＡＴＰ酶活性的影响。方法 利用沙土鼠全脑缺血模型，观察全脑缺血１０分及再灌２０分，６０分时，低温，巴曲酶及巴曲酶复合低温对海马组织Ｎａ＾＋－Ｋ＾＋－ＡＴＰ酶，Ｃａ＾２＋－ＡＴＰ酶活性的影响。     

维生素E对老化大鼠肝细胞线粒体脂质过氧化损害的防治

观察６、１２、１８和２４月龄大重肝细胞（ＨＣ）线粒体丙二醛（ＭＤＡ），超氧化物歧化酶（ＳＯＤ）、谷胱甘肽过氧化物酶（ＧＰＤ），过氧化氢酶（ＣＡＴ）以及肝组织三磷酸腺苷（ＡＴＰ）含量。结果表明，１８、２４月龄大鼠ＨＣ线粒体ＭＤＡ含量较６月龄分别升高了３３．８％和４９．２％（Ｐ〈０．０１）。同时ＳＯＤ、ＧＰＤ活性及ＡＴＰ含量均显著降低，维生素（ＶＥ）可显著提高ＨＣ线粒体抗氧化酶活性，在一定程度上减轻脂     

大鼠异位小肠移植酶组织化学的监测

观察大鼠异位小肠移植后应用环孢素Ａ（ＣｓＡ）及不用药条件下移植肠的乙酰胆碱酯酶（ＡｃｈＥ），单胺氧化酶（ＭＡＯ），腺甙三磷酸酶（ＡＴＰａｓｅ）的活性变化。实验结果提示，未用药组术后排斥反应呈进行性发展，上述酶的活性相应呈进行性下降；应用ＣｓＡ治疗者没有发生排斥反应时，ＡｃｈＥ及ＡＴＰａｓｅ能维持接近于正常水平，当发生排斥时，在病理检查出现改变前３天ＡｃｈＥ及ＡＴＰａｓｅ能维持接近于正常水平，当发生     

犬急性出血坏死性胰腺炎肺Ⅱ型上皮细胞的酶组织化学改变

急性出血坏死性胰腺炎（ＡＨＮＰ）易并发呼吸衰竭。本研究采用犬制作ＡＨＮＰ肺损伤模型，对肺Ⅱ型上皮细胞辅酶Ⅰ黄递酶等１１种酶进行观察。结果显示：ＡＨＮＰ组肺Ⅱ型上皮细胞定位于内质网的酶有辅酶Ⅱ黄递酶和中性非特异性脂酶；定位于线粒体的酶有细胞色素氧化酶、辅酶Ⅰ黄递酶、苹果酸脱氢酶和异柠檬酸脱氢酶；与细胞浆有关的酶有乳酸脱氢酶、α－甘油磷酸脱氢酶和葡萄糖－６－磷酸脱氢酶。与对照组比较，ＡＨＮＰ组上述酶的活性明显下降，而与溶酶体有关的酸性磷酸酶和β－葡萄糖胺则显著升高。作者认为，ＡＨＮＰ组上述酶活性的明显下降，导致肺Ⅱ型上皮细胞糖代谢严重障碍和表面活性物质合成减少，从而引起肺不张、肺通气功能障碍，是引起呼吸衰竭的重要原因之一。     

H^＋,K^＋—ATP酶：在肾脏病理生理中的调节作用

分子生物学、微穿刺和微灌注等技术的联合应用研究对于阐明Ｈ＾＋，Ｋ＾＋－ＡＴＰ酶的分子结构与功能表达已取得了一定的认识，并对其亚型转运体的性质也有了足够的了解，且已克隆出大部分亚型的转运体。本文对Ｈ＾＋，Ｋ＾＋－ＡＴＰ酶及亚型分布结构，表达调节，生化特征以及在肾脏生理、病理过程中所发挥的重要作用机制进行综述。     

β—葡萄糖醛酸酶,磷脂酶A2在急性坏死性胰腺炎及并发感染中？…

为探讨血清β－葡萄糖醛酸酶，磷脂酶Ａ２（ＰＬＡ２）在急性坏死性胰腺炎（ＡＮＰ）及并发感染中的作用，采用杂种犬，通过向主胰管内注入牛磺胆酸钠和胰蛋白酶复制犬ＡＮＰ模型，术后第１，２，４，７天测定血清β葡萄糖醛酸酶，ＰＬＡ２和胰淀粉酶（ＡＭＹ）活性；每天抽血作细菌培养，第七天处死动物后，脏器作细菌培养，结果显示；ＡＮＰ组犬血清β－葡萄糖醛酸酶，磷脂酶Ａ２水平各时间点均高于对照组１～２倍，ＡＭＹ高出对照     

抗DNA酶B在急性肾小球肾炎诊断的临床应用

抗ＤＮＡ酶Ｂ在急性肾小球肾炎诊断的临床应用董太明黄震东符永恒吴红穗陈剑光陈志红罗健Ａ组溶血性链球菌（ＧＡＳ）感染导致的急性肾小球肾炎（ＡＧＮ）的病原学诊断，国内通常采用抗溶血素Ｏ（ＡＳＯ），到目前为止，尚未见到采用抗脱氧核糖核酸酶Ｂ（抗ＤＮＡ酶Ｂ）微...     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.